DN504 — Quad Compressor/Limiter

The DN504 packs four independent channels of compression and limiting into a single rack unit, designed for engineers who need consistent dynamics processing across multiple sources without the rack space or cost of four mono units. The same automatic attack/release circuit that gave the DN500 its near-transparent character is implemented here, scaled to four-channel operation.

Compression Architecture

Each channel offers compression threshold from -30 dB to +20 dB and ratio from 1:1 to 50:1. At the 50:1 setting the channel operates as a fast-acting peak limiter. Frequency response is 20 Hz to 20 kHz ±0.5 dB; dynamic range is greater than 115 dB unweighted. Maximum output level is +21 dBu. The automatic attack and release circuitry handles programme material with minimal audible artefact.

Connectivity

Inputs and outputs are on 3-pin XLR; an external side-chain input on balanced 1/4" TRS is provided per channel for frequency-conscious work. The unit occupies a single rack unit and weighs 8.8 lb.

Application

Multi-channel drum compression in live FOH, four-way speaker-system protection in installations, broadcast multi-source loudness control. The 50:1 limiter mode is the practical safety net on power amplifier inputs across permanent installs.

Specification Highlights

• Four-channel compressor / limiter, 1U rackmount
• Threshold -30 dB to +20 dB, ratio 1:1 to 50:1
• Frequency response 20 Hz - 20 kHz ±0.5 dB
• Dynamic range >115 dB unweighted
• Max output +21 dBu
• Balanced XLR I/O, 1/4" TRS side-chain per channel
• Auto attack/release for transparent programme compression